wifi problem

Hi guys I'm new on ubuntu, now i have a problem with my wifi connection, In settings I get: "no wifi adapter found"
I followed many instruction I read here but still it's not working.
I installed ubuntu 18.04 on my hp notebook, with rltk drivers.

when I type this command: ifconfig wlan0 up
I get:
wlan0: ERROR while getting interface flags: No such device

and when I type this: iwconfig
I only get this:

enp2s0 no wireless extensions.
lo no wireless extensions.

what can i do?